Process of reproducing surface inlays on panels of composite fibrous materials



vMa ch 2 3- E. 'c. LOETSCHER REPRODUCING SURFACE INLAYS' 0N PANELS OF COMPOSITE FIBRQUS MATERIAL PROCESS OF Filed F eb. 20, 1930 Jzaezakw I 7? C. 0a 0 FY W Patented Mar. 21, 1933 UNITED STATES PATENT OFFICE E1711 0. LO ETSCHER, OF DUIBUQUE, IOWA PROCESS or nnrnonuomo soaraon INLAYS on PANELS or oomrosrrn muons MATERIALS Application filed February 20, 1930. Serial No. 429,932.

This invention relates to improvements in processes for reproducing surface inlays on panels having a base of compressed cellulose fibrous material, and more particularly to the art of producing doors, panels, Wood work and other mill products of a composite fibrous material as a substitute for the more expensive natural hard woods ordinarily used in their manufacture.

The general characteristics of the composite material and the processes of its manufacture have been disclosed in several previous applications filed by me, among which may be mentioned Serial No. 312,744 filed October 15, 1928, Serial Nos. 377,917 and 377,918 filed July 12, 1929, and Serial No. 413,454 filed December 12, 1929.

The object of the present invention is to provide a process for the ornamentation of the surfaces of doors, panels and the like in simulation of inlayed designs such as are obtained in natural woods by inlaying thin strips of wood of a contrasting color or graining into the surface of the work.

. The process by which the same results can be produced on thesurface of a panel of a composite fibrous material is illustrated in the accompanying drawing in which Figure 1 is a view in elevation of a showing the inlay work.

Figure 2 is a diagrammatic view showing the manner in which the several layers of fibrous material are assembled.

Figure 3 is a view in cross section through the panel taken on line 33 of Figure 1,

showing the same materials after they have been compressed to form the finished panel.

Figure 4 is a perspective View of the mitered ends of the superimposed inlay strips,

0 and Figure 5 is a detail view in cross section showing the inlay applied to a panel having portions of different thickness.

Referring first to the general process involved in the manufacture of the material into the form of a panel, the base or foundation of the same is a slab or mat 1 of a cellulose fibrous substance such as cornstalk fiber, shredded or otherwise reduced to a pulp, and

thence partially compressed into the form of panel a mat of uniform thickness, but adapted to be further compressed to its final .density and thickness.

The mat 1 thus prepared and thoroughly dried is then coated with a solution of bakelite or other resinous varnish and subjected to further drying in an oven to drive off the excess of the'solvents in the varnish. Over the sized faces of the mat or base 1 are applied layers 2, 2 of ordinary plain kraft pato per Which have been previously impregnated with a 40% to 50% solution of bakelite, these sheets being termed bakelized paper to indicate their character after treatment.

Superimposed upon the sheets 2, 2 of plain c5 bakelized kraft paper are sheets 3, 3 of a thinner paper of a grade known as alpha cellulose, which has beenprinted with an overall design reproducing the color and graining of a natural wood, such as mahogany, these 7o sheets also having been bakelized, that is, subjected to a treatment of impregnation with. a solution of bakelite varnish of from 50% to strength. In each case these bakelized sheets are dried before being used, :5 so that the solvent has been driven off, leaving only the bakelite impregnation.

Assuming now that the inlay designs to be reproduced are rectangular frames arranged symmetrically on both faces of the panel, each frame being made up of two parallel bands or strips 4 and 5' abutting edge to edge, and mitered at each corner. These bands represent inlayed strips of wood of different and contrasting colors and graining. For instance, the panel surface may be colored and grained in imitation of mahogany in which the grain runs lengthwise, the outer L band 4may be mahogany of a different color and graining in which the grain runs lengthwise at top and bottom as well as at the sides,

and the inner band 5 may be a burl walnut.

These bands 4 and 5 are preferably produced fromfnarrow strips of a suitable paper, such as alpha cellulosepap'er, colored and printed in imitation of the particular woods selected, and then impregnated with bakelite varnish and dried. The printing of the paper for the bands 4 and 5 as well asthe large sheets 3, 3 covering the surface .ofthe 1 photographic negatives of the natural woods, 5 these processes being well known in the art.

The application of the bands or strips of paper to the panel consists of the following steps: Longitudinal and transverse strips of the grained bakelized paper, 4a and 4b, having a width equal to that of both bands 4 and 5 (Figure 1) are cut to length and trimmed for mitering at their ends, and then super imposed upon the sheets 3, 3 in the form of a rectangular mitered frame, and then still narrower strips 505, 56 for the inner band 5 are also cut and trimmed for mitering at their ends and superimposed upon the outer mar ginal portions of the strips 4a, 4b with their outer edges in register. -In this manner the narrower strips 5a, 5?; cover substantially one-half the width of the underlying strips 8 4a, 4b with the exposed inner edge portion forming the inner band 5 (Figure 1).

In practice, the several layers of paper 2 and 3 and the inlay strips would be assembled into a single laminated sheet and then laid over the surfaces of the mat, the surfaces of the paper being ordinarily tacky enough to cause the items to adhere to each other, or if not, rendered so by softening the bakelite with alcohol or applying a suitable adhesive to their surfaces. Hence Figure 2 is not intended to show the preferred method of assembling the several, layers of paper upon the mat, but rather their relative positions in the assembly. r

When the materials have thus been assembled, they are ready to be placed in a hydraulic press which is equipped with special platens or die plates of a hollow construction with connections so that steam and water can be circulated through them for heat ingand cooling purposes. Carefully polished plates are preferably inserted between the surfaces of the panel and the platens so as to insure a perfectly smooth surface finish.

After the composite panel is placed in the press, steam is turned into the platens for a short period of time before the pressure is applied, so as to heat the inaterialsup to, say, 120 or 150 centigrade, and thus soften the bakelite. The pressure is-now applied from 100 to 500 pounds per square inch, de

panel, t epressure being maintained for sevoff and water circulated through the platens to restore the normal temperature conditions I 3 wherein themat or base 1 has been com-.

. pressed to a substantially greater densi and decreased thickness, and the strips 40, 4

and 5a, 56 being pressed into the layersof pendin on the desired density ofthe finished 1 eral minutes, whereupon the steam is turned paper 2 and 3 beneath, the latter in turn "being impressed into the mat 1, thus producmg flat smooth faces on both sides of the panel.

It may bei'fstated that in the process of compressing thesuperimposed layers of aper in the presence of heat, the bakelite 1n the paper becomes soft and tends to flow, thus sealing the joints between the edges of the inlay strips and otherwise uniting the layers together without roughness or surface indication of joints at the ed es. I

Figure 5 shows a modi ed form of inlaid panel in which the outer marginal portion 6 is considerably thicker than the central portion 7 and the intermediate portion 8, covered by the inlay'strips 9 and 10, are beveled and offset into different planes to give the effect of an inlayed moulding" between a heavy Outer frame and a thin central panel. uch a panel requires a mat having a thickened marginal portion, and die plates with sunken areas conforming to the surface contour of the finished panel, but otherwise the process of inlaying is the same.

While I have illustrated a rather simple inlay design'on the surface of the panel, it is to be understood that more intricate designs can be as readily produced, in fact any.

that can be executed in the wood-working art can be reproduced in the surface of a panel of composite fibrous structure with,

marked accuracy and faithful imitation of inlay work which can only be produced-in pagural woods at relatively great expense and a or.

Having set forth a preferred embodiment of my invention, I claim: V 1 1. he process of producing inlay designs substance-to the surface of the base, laying strips of fibrous material upon the covering in the surface of a composite material con-Q sisting of providing a baseof a compressible material, applying a surfacecovering of thin .fibrous material impregnated witha resinous material in the outline of-the inlay and compressing the material whereby the'same is reduced to a 'uniformden'sity and thicknesswith the. inlaystrips flush with the surface thereof. 4

2. The process of producing inlay designs in the surface of a -composite material consisting (if covering the surfaceof'a base'of a plying inlay strips of similarly treated fi rous material of a contrasting co or or design upon the covered surface of the base and heating and compressing the material sufiis int-hesurface of a; composite material consiating of compressible fibrous material withv a thin, sheet of resin impregnated fibrous material,

providing a base of a compressible '1 fibrous material, covering the surface of the base with a thin sheet of fibrous material ornamented and impregnated with a resinous substance, laying superimposed layers of fibrous, material cut and arranged in the design of the desired inlay upon the covered surface of the base and compressing the as sembled materials in the presence of heat suf- -ficient to press the layers of inlay material flush with the finished surface of the base.

4. The process of producing inlay designs in the surface of a composite material consisting of providing a base of a compressible cellulose fiber, coating the surface of the base with a thin layer of fibrous material impregnated with a resinous substance and ornamented to represent wood graining, laying strips of the same treated fibrous material but ornamented in a contrasting grain of wood, upon the grained surface of the base,

applying narrower strips of the same but differently rained material upon the first mentione strips, and finally compressing the materials in the-presence of heat to reduce the same to a uniform thickness and flush with the finished surfaces.

5. The rocess of producing inlay designs in the sur ace of a composite material having a base of cellulose fiber, consisting of applying a sheet of natural grainedfibrous material impregnated with a phenol condensation product over the surface of the base material, preparing contrasting inlay strips of a similarly treated fibrous material and arranging them one upon the other on the surface of the first grainedsheet to form the inlay pattern, and compressing I the material in the presence of heat sufliciently to compress the same to a uniform thickness and a smooth surface finish.

, Signed at Dubuque, Iowa, this-14th day of February, 1930.

' EMIL C. LOETSCHER. 

